There are a certain number of known approaches for supporting conventional aircraft engines mounted beneath the wings or at the tail section of the fuselage. Techniques have also been developed for supporting engines of the “open rotor pusher” type, namely those comprising a gas generator and a receiver having a pair of contrarotating unducted rotors positioned to the rear of the gas generator.
However, in the case of engines of the “open rotor puller” type, in which the pair of unducted contrarotating rotors is positioned forward of the gas generator, the techniques applied to conventional engines or to engines of the “open rotor pusher” type are not suitable.
Specifically, engines of the “open rotor puller” type have their pair of rotors forward of the pylon connecting the engine to the aircraft airframe. As a result, it is necessary to provide a relatively large distance between the rotors and the leading edge of the pylon in order to avoid detrimental aerodynamic interactions between the air propelled by the rotors and the pylon. This distance is typically at minimum of the order of 1 meter.
This constraint dictates that the center of gravity of such an engine be shifted a long way forward with respect to the pylon, thereby requiring a novel approach in terms of how the engine forces are reacted by the pylon.